It's going to be 3 months now precisely 
Well I've already posted detailed reviews about this device on incpak.com and in this same very thread but just to add I'm still very satisfied with the device and plans to keep it for atleast six more months and yes I'm using it as my main phone 
Os version : Though final LP is released but it's below average and next release with xui is expected in 1st week of december. So far stable os is official KK
Custom support: Yes lit of custom roms are available on bbs.infinixmobility (including cm 12.1) , few very stable , few buggy. So if you get bored with stock os you can change the flavour. All custom roms have bugs few have very less and almost negligible.
Battery : Depends upon Os. Stock KK is good enough with 4:30 plus sot. Custom roms vary . Cm 12 has monstrous battery backup on zero 2. Touches 5:30 and around 20 hrs standby.
Peroformance: I'll simply define in one line No Lag at all , doesn't matter what you're doing
Cam: Both cams are exceptionally good , front cam is ideal for selfie lovers.
Hope it helps 